Calorimetric and Thermomechanical Properties of Titanium-Based Orthodontic Wires: DSC–DMA Relationship to Predict the Elastic Modulus

Orthodontic treatment is strongly dependent on the loads developed by metal wires, and the choice of an orthodontic archwire should be based on its mechanical performance. The desire of both orthodontists and engineers would be to predict the mechanical behavior of archwires. To this aim, Gum Metal (Toyota Central R&L Labs., Inc.), TMA (ORMCO), 35°C Copper NiTi (SDS ORMCO), Thermalloy Plus (Rocky Mountain), Nitinol SE (3M Unitek), and NiTi (SDS ORMCO) were tested according to dynamic mechanical analysis and differential scanning calorimetry. A model was also developed to predict the elastic modulus of superelastic wires. Results from experimental tests have highlighted that superelastic wires are very sensitive to temperature variations occurring in the oral environment, while the proposed model seems to be reliable to predict the Young’s modulus allowing to correlate calorimetric and mechanical data. Furthermore, Gum Metal wire behaves as an elastic material with a very low Young’s modulus, and it can be particularly useful for the initial stage of orthodontic treatments.

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Theoretical and experimental investigation of MWCNT dispersion effect on the elastic modulus of flexible PDMS/MWCNT nanocomposites

Nanotechnology Reviews ◽

10.1515/ntrev-2022-0006 ◽

2021 ◽

Vol 11 (1) ◽

pp. 55-64

Author(s):

Pardis Ghahramani ◽

Kamran Behdinan ◽

Rasool Moradi-Dastjerdi ◽

Hani E. Naguib

Keyword(s):

Elastic Modulus ◽

Young’S Modulus ◽

Young's Modulus ◽

Testing Machine ◽

Experimental Tests ◽

Weight Fraction ◽

Experimental Results ◽

Multiwalled Carbon ◽

Displacement Mode ◽

Theoretical Predictions

Abstract In this article, Young’s modulus of a flexible piezoresistive nanocomposite made of a certain amount of multiwalled carbon nanotube (MWCNT) contents dispersed in polydimethylsiloxane (PDMS) has been investigated using theoretical and experimental approaches. The PDMS/MWCNT nanocomposites with the governing factor of MWCNT weight fraction (e.g., 0.1, 0.25, and 0.5 wt%) were synthesized by the solution casting fabrication method. The nanocomposite samples were subjected to a standard compression test to measure their elastic modulus using Instron Universal testing machine under force control displacement mode. Due to the costs and limitations of experimental tests, theoretical predictions on the elasticity modulus of such flexible nanocomposites have also been performed using Eshelby–Mori–Tanaka (EMT) and Halpin–Tsai (HT) approaches. The theoretical results showed that HT’s approach at lower MWCNT contents and EMT’s approach at higher MWCNT contents have a better agreement to experimental results in predicting the elastic modulus of PDMS/MWCNT nanocomposites. The experimental results indicated that the inclusion of MWCNT in the PDMS matrix resulted in a noticeable improvement in Young’s modulus of PDMS/MWCNT nanocomposite at small values of MWCNT contents (up to w f = 0.25%); however, exceeding this nanofiller content did not elevate Young’s modulus due to the emergence of MWCNT agglomerations in the nanocomposite structure.

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Cardiomyocyte mechanodynamics under conditions of actin remodelling

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2019.0081 ◽

2019 ◽

Vol 374 (1786) ◽

pp. 20190081 ◽

Cited By ~ 5

Author(s):

Ricardo H. Pires ◽

Nithya Shree ◽

Emmanuel Manu ◽

Ewa Guzniczak ◽

Oliver Otto

Keyword(s):

Stem Cells ◽

Real Time ◽

Young’S Modulus ◽

Mechanical Performance ◽

Young's Modulus ◽

Mechanical Analysis ◽

Adherent Cells ◽

Filamentous Actin ◽

Important Indicator ◽

Compound Exposure

The mechanical performance of cardiomyocytes (CMs) is an important indicator of their maturation state and of primary importance for the development of therapies based on cardiac stem cells. As the mechanical analysis of adherent cells at high-throughput remains challenging, we explore the applicability of real-time deformability cytometry (RT-DC) to probe cardiomyocytes in suspension. RT-DC is a microfluidic technology allowing for real-time mechanical analysis of thousands of cells with a throughput exceeding 1000 cells per second. For CMs derived from human-induced pluripotent stem cells, we determined a Young's modulus of 1.25 ± 0.08 kPa which is in close range to previous reports. Upon challenging the cytoskeleton with cytochalasin D (CytoD) to induce filamentous actin depolymerization, we distinguish three different regimes in cellular elasticity. Transitions are observed below 10 nM and above 10 3 nM and are characterized by a decrease in Young's modulus. These regimes can be linked to cytoskeletal and sarcomeric actin contributions by CM contractility measurements at varying CytoD concentrations, where we observe a significant reduction in pulse duration only above 10 3 nM while no change is found for compound exposure at lower concentrations. Comparing our results to mechanical cell measurements using atomic force microscopy, we demonstrate for the first time to our knowledge, the feasibility of using a microfluidic technique to measure mechanical properties of large samples of adherent cells while linking our results to the composition of the cytoskeletal network. This article is part of a discussion meeting issue ‘Single cell ecology'.

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The Effect of Boron Nitride on the Thermal and Mechanical Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Nanomaterials ◽

10.3390/nano8110940 ◽

2018 ◽

Vol 8 (11) ◽

pp. 940 ◽

Cited By ~ 6

Author(s):

Mualla Öner ◽

Gülnur Kızıl ◽

Gülşah Keskin ◽

Celine Pochat-Bohatier ◽

Mikhael Bechelany

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Boron Nitride ◽

Young’S Modulus ◽

Mechanical Performance ◽

Young's Modulus ◽

Filler Concentration ◽

Gravimetric Analysis ◽

Thermal And Mechanical Properties ◽

Scanning Calorimetry

The thermal and mechanical properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) composites filled with boron nitride (BN) particles with two different sizes and shapes were studied by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), thermal gravimetric analysis (TGA) and mechanical testing. The biocomposites were produced by melt extrusion of PHBV with untreated BN and surface-treated BN particles. Thermogravimetric analysis (TGA) showed that the thermal stability of the composites was higher than that of neat PHBV while the effect of the different shapes and sizes of the particles on the thermal stability was insignificant. DSC analysis showed that the crystallinity of the PHBV was not affected significantly by the change in filler concentration and the type of the BN nanoparticle but decreasing of the crystallinity of PHBV/BN composites was observed at higher loadings. BN particles treated with silane coupling agent yielded nanocomposites characterized by good mechanical performance. The results demonstrate that mechanical properties of the composites were found to increase more for the silanized flake type BN (OSFBN) compared to silanized hexagonal disk type BN (OSBN). The highest Young’s modulus was obtained for the nanocomposite sample containing 1 wt.% OSFBN, for which increase of Young’s modulus up to 19% was observed in comparison to the neat PHBV. The Halpin–Tsai and Hui–Shia models were used to evaluate the effect of reinforcement by BN particles on the elastic modulus of the composites. Micromechanical models for initial composite stiffness showed good correlation with experimental values.

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A UNIQUE APPROACH TO EXPERIMENTAL CHARACTERIZATION OF A THERMOSETTING POLYMER MATRIX FOR ICME FRAMEWORKS

10.12783/asc36/35814 ◽

2021 ◽

Author(s):

MICHAEL N. OLAYA ◽

SAGAR PATIL ◽

GREGORY M. ODEGARD ◽

MARIANNA MAIARÙ

Keyword(s):

Tensile Strength ◽

Young’S Modulus ◽

Young's Modulus ◽

Cure Kinetics ◽

Image Correlation ◽

Scanning Calorimetry ◽

Mixing Ratios ◽

Fitting Procedure ◽

Amine Content

A novel approach for characterization of thermosetting epoxy resins as a function of the degree of cure is presented. Density, cure kinetics, tensile strength, and Young’s modulus are experimentally characterized across four mixing ratios of DGEBF/DETDA epoxy. Dynamic differential scanning calorimetry (DSC) is used to characterize parameters for a Prout-Thompkins kinetic model unique to each mixing ratio case through a data fitting procedure. Tensile strength and Young’s modulus are then characterized using stress-strain data extracted from quasi-static, uniaxial tension tests at room temperature. Strains are measured with the 2-D digital image correlation (DIC) optical strain measurement technique. Strength tends to increase as amine content use in the formulation increases. The converse trend is observed for Young’s modulus. Density measurements also reveal an inverse relationship with amine content.

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Indentation Tests for Sintered Silver in Die-Attach Interconnection After Thermal Cycling

Journal of Electronic Packaging ◽

10.1115/1.4053028 ◽

2021 ◽

Author(s):

Fei Qin ◽

Shuai Zhao ◽

Yanwei Dai ◽

Lingyun Liu ◽

Tong An ◽

...

Keyword(s):

Thermal Cycling ◽

Young’S Modulus ◽

Mechanical Performance ◽

Young's Modulus ◽

Silver Layer ◽

Thermal Cycles ◽

Nano Indentation ◽

Die Attach ◽

Indentation Tests ◽

Sintered Silver

Abstract Thermo-mechanical reliability assessment for sintered silver is a crucial issue as sintered silver is a promising candidate of die-attachment materials for power devices. In this paper, the nano-indentation tests are performed for sintered silver in typical die-attach interconnection under different thermal cycles. Based on thermal cycling test, the Young's modulus and hardness of sintered silver layer have been presented. It is found that the Young's modulus and hardness of sintered silver layer changes slightly although the microstructure of sintered silver also presents some variations. The stress and strain curves for different thermal cycling tests for sintered silver based on reverse analysis of nano-indentation are also given. The results show that the elastoplastic constitutive equations change significantly after thermal cycling tests, and the yielding stress decreases remarkably after 70 thermal cycles. The experimental investigation also show that the cracking behaviors of sintered silver depends on its geometry characteristics, which implies that the possible optimization of sintered silver layer could enhance its thermo-mechanical performance.

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Influence of 1D and 2D Carbon Fillers and Their Functionalisation on Crystallisation and Thermomechanical Properties of Injection Moulded Nylon 6,6 Nanocomposites

Journal of Nanomaterials ◽

10.1155/2014/670261 ◽

2014 ◽

Vol 2014 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Fabiola Navarro-Pardo ◽

Ana L. Martínez-Hernández ◽

Victor M. Castaño ◽

José L. Rivera-Armenta ◽

Francisco J. Medellín-Rodríguez ◽

...

Keyword(s):

Mechanical Analysis ◽

Thermomechanical Properties ◽

Reduced Form ◽

Scanning Calorimetry ◽

Graphene Nanocomposites ◽

Moulding Process ◽

Nylon 6,6 ◽

Injection Moulding Process ◽

The One ◽

Carbon Fillers

Carbon nanotubes (CNTs) and graphene were used as reinforcing fillers in nylon 6,6 in order to obtain nanocomposites by using an injection moulding process. The two differently structured nanofillers were used in their pristine or reduced form, after oxidation treatment and after amino functionalisation. Three low nanofiller contents were employed. Crystallisation behaviour and perfection of nylon 6,6 crystals were determined by differential scanning calorimetry and wide angle X-ray diffraction, respectively. Crystallinity was slightly enhanced in most samples as the content of the nanofillers was increased. The dimensionality of the materials was found to provide different interfaces and therefore different features in the nylon 6,6 crystal growth resulting in improved crystal perfection. Dynamical, mechanical analysis showed the maximum increases provided by the two nanostructures correspond to the addition of 0.1 wt.% amino functionalised CNTs, enhancing in 30% the storage modulus and the incorporation of 0.5 wt.% of graphene oxide caused an increase of 44% in this property. The latter also provided better thermal stability when compared to pure nylon 6,6 under inert conditions. The superior properties of graphene nanocomposites were attributed to the larger surface area of the two-dimensional graphene compared to the one-dimensional CNTs.

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The Effect of POSS Type on the Shape Memory Properties of Epoxy-Based Nanocomposites

Molecules ◽

10.3390/molecules25184203 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4203

Author(s):

Avraham I. Bram ◽

Irina Gouzman ◽

Asaf Bolker ◽

Noam Eliaz ◽

Ronen Verker

Keyword(s):

Transition Temperature ◽

Shape Memory ◽

Crosslinking Density ◽

Mechanical Analysis ◽

Thermomechanical Properties ◽

Space Environment ◽

Scanning Calorimetry ◽

Space Applications ◽

Curing Conditions ◽

Oligomeric Silsesquioxane

Thermally activated shape memory polymers (SMPs) can memorize a temporary shape at low temperature and return to their permanent shape at higher temperature. These materials can be used for light and compact space deployment mechanisms. The control of transition temperature and thermomechanical properties of epoxy-based SMPs can be done using functionalized polyhedral oligomeric silsesquioxane (POSS) additives, which are also known to improve the durability to atomic oxygen in the space environment. In this study, the influence of varying amounts of two types of POSS added to epoxy-based SMPs on the shape memory effect (SME) were studied. The first type contained amine groups, whereas the second type contained epoxide groups. The curing conditions were defined using differential scanning calorimetry and glass transition temperature (Tg) measurements. Thermomechanical and SME properties were characterized using dynamic mechanical analysis. It was found that SMPs containing amine-based POSS show higher Tg, better shape fixity and faster recovery speed, while SMPs containing epoxide-based POSS have higher crosslinking density and show superior thermomechanical properties above Tg. This work demonstrates how the Tg and SME of SMPs can be controlled by the type and amount of POSS in an epoxy-based SMP nanocomposite for future space applications.

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Kinetics of Capability Aging in Ti-13Nb-13Zr Alloy

Crystals ◽

10.3390/cryst10080693 ◽

2020 ◽

Vol 10 (8) ◽

pp. 693 ◽

Cited By ~ 1

Author(s):

Myoungjae Lee ◽

In-Su Kim ◽

Young Hoon Moon ◽

Hyun Sik Yoon ◽

Chan Hee Park ◽

...

Keyword(s):

Mechanical Strength ◽

Young’S Modulus ◽

Mechanical Performance ◽

Young's Modulus ◽

Solution Treatment ◽

High Strength ◽

Biomedical Implant ◽

13Zr Alloy ◽

American Society ◽

Kinetics Of

Metals for biomedical implant applications require a simultaneous achievement of high strength and low Young’s modulus from the viewpoints of mechanical properties. The American Society for Testing and Materials (ASTM) standards suggest two types of processing methods to confer such a mechanical performance to Ti-13Nb-13Zr alloy: solution treatment (ST) and capability aging (CA). This study elucidated the kinetics of CA process in Ti-13Nb-13Zr alloy. Microstructural evolution and mechanical change were investigated depending on the CA duration from 10 min to 6 h. The initial ST alloy possessed the full α′-martensitic structure, leading to a low strength, low Young’s modulus, and high ductility. Increasing CA duration increased mechanical strength and Young’s modulus in exchange for the reduction of ductility. Such a tendency is attributed to the decomposition of α′ martensite into (α+β) structure, particularly hard α precipitates. Mechanical compatibility (i.e., Young’s modulus compensated with a mechanical strength) of Ti-13Nb-13Zr alloy rarely increased by changing CA duration, suggestive of the intrinsic limit of static heat treatment.

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Biocomposites from Rice Straw Nanofibers: Morphology, Thermal and Mechanical Properties

Materials ◽

10.3390/ma13092138 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2138 ◽

Cited By ~ 1

Author(s):

José Carlos Alcántara ◽

Israel González ◽

M. Mercè Pareta ◽

Fabiola Vilaseca

Keyword(s):

Rice Straw ◽

Mechanical Performance ◽

Cellulose Nanofibers ◽

Nucleating Agent ◽

Mechanical Analysis ◽

Nanocomposite Films ◽

Chemical Extraction ◽

Poly Vinyl Alcohol ◽

Scanning Calorimetry ◽

The Matrix

Agricultural residues are major potential resources for biomass and for material production. In this work, rice straw residues were used to isolate cellulose nanofibers of different degree of oxidation. Firstly, bleached rice fibers were produced from the rice straw residues following chemical extraction and bleaching processes. Oxidation of rice fibers mediated by radical 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) at pH 10 was then applied to extract rice cellulose nanofibers, with diameters of 3–11 nm from morphological analysis. The strengthening capacity of rice nanofibers was tested by casting nanocomposite films with poly(vinyl alcohol) polymer. The same formulations with eucalyptus nanofibers were produced as comparison. Their thermal and mechanical performance was evaluated using thermogravimetry, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. The glass transition of nanocomposites was shifted to higher temperatures with respect to the pure polymer by the addition of rice cellulose nanofibers. Rice nanofibers also acted as a nucleating agent for the polymer matrix. More flexible eucalyptus nanofibers did not show these two phenomena on the matrix. Instead, both types of nanofibers gave similar stiffening (as Young’s modulus) to the matrix reinforced up to 5 wt.%. The ultimate tensile strength of nanocomposite films revealed significant enhancing capacity for rice nanofibers, although this effect was somehow higher for eucalyptus nanofibers.

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Graphene oxide and zinc oxide decorated chitosan nanocomposite biofilms for packaging applications

Journal of Polymer Engineering ◽

10.1515/polyeng-2019-0240 ◽

2020 ◽

Vol 40 (2) ◽

pp. 152-157 ◽

Cited By ~ 4

Author(s):

Pınar Terzioglu ◽

Yasin Altin ◽

Ayse Kalemtas ◽

Ayse Celik Bedeloglu

Keyword(s):

Tensile Strength ◽

Zinc Oxide ◽

Graphene Oxide ◽

Composite Film ◽

Young’S Modulus ◽

Mechanical Performance ◽

Young's Modulus ◽

Chitosan Film ◽

Oxide Composite ◽

Wide Range

AbstractRecently, due to sustainable development and environmental protection policies, there is increasing interest in the development of new biodegradable polymer-based multifunctional composites. Chitosan is one of the most remarkable and preferred biopolymers, which is environmentally friendly as well as renewable, biocompatible, and inexpensive. Though it has a wide range of potential applications, the major limitation of chitosan – the problem of poor mechanical performance – needs to be solved. In this work, graphene oxide was first produced and then used to manufacture a chitosan/graphene oxide/zinc oxide composite film through a casting method. The properties of the chitosan film and the chitosan/graphene oxide/zinc oxide composite film were investigated using Fourier transform infrared spectroscopy, mechanical, thermal gravimetric, and ultraviolet (UV)-visible spectroscopy analyses. The results showed that the incorporation of graphene oxide and zinc oxide into the chitosan matrix resulted in enhanced mechanical properties and thermal stability of chitosan biocomposite films. The graphene oxide- and zinc oxide-reinforced chitosan film showed 2527 MPa and 55.72 MPa of Young’s modulus and tensile strength, respectively, while neat chitosan showed only 1549 MPa and 37.91 MPa of Young’s modulus and tensile strength, respectively. Conversely, the addition of graphene oxide decreased the transmittance, notably in the UV region.

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